All Systems Go is a phrase used to indicate that everything is READY and in order for a task or event to begin. In this crossword, the solutions READY (5 letters), AOK (3 letters) and AOKAY (5 letters) all refer to this phrase. READY is an adjective meaning prepared or in a state of readiness, while AOK and AOKAY are both informal ways of saying 'all is okay'. Together, these solutions indicate that everything is READY and in order for a task or event to begin.